1. Field of the Invention
The present invention relates to a switch device that is used in an electronic apparatus such as a timepiece, a cellular phone, and a portable terminal, and a timepiece.
2. Description of the Related Art
In recent years, a switch device for a wristwatch is known in which a mounting pipe is fitted into a fitting hole of a wristwatch case, a shaft portion of a button member is slidably inserted into the mounting pipe, the shaft portion of the button member protruding from the mounting pipe and the head of the shaft portion formed on its outer end are covered with a waterproof sheet, and the waterproof sheet is attached to the outer surface of the wristwatch case via a fixing member so as to achieve waterproofness, as described in Japanese Patent Application Laid-Open (Kokai) Publication No. 2009-133859.
This type of switch device having the waterproof sheet made of a soft synthetic resin such as urethane resin or silicone resin is structured such that, when the button member is pressed, the waterproof sheet deforms elastically in response to this press operation, and the elastic deformation of the waterproof sheet causes the button member to slide and come in contact with a switch contact inside the wristwatch case, which results in a switching operation.
However, in this switch device, the waterproof sheet is not easily deformed if it is thick, in which case a larger pressure load is required when the button member is pressed. As a result, the operability of the button member is deteriorated. If the waterproof sheet is thinner, it is elastically deformed more easily. However, in this case, the waterproof sheet is damaged more easily, and therefore the waterproofness cannot be ensured. In addition, since the waterproof sheet is made of a soft synthetic resin, it is easily deteriorated regardless of whether it is thick or thin.
An object of the present invention is to provide a switch device and a timepiece that can ensure waterproofness and improve operability.